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We demonstrate self-folding of precisely patterned, optically transparent, all-polymeric containers and describe their utility in mammalian cell and microorganism encapsulation and culture. The polyhedral containers, with SU-8 faces and biodegradable polycaprolactone (PCL) hinges, spontaneously assembled on heating. Self-folding was driven by a minimization of surface area of the liquefying PCL hinges within lithographically patterned two-dimensional (2D) templates. The strategy allowed for the fabrication of containers with variable polyhedral shapes, sizes and precisely defined porosities in all three dimensions. We provide proof-of-concept for the use of these polymeric containers as encapsulants for beads, chemicals, mammalian cells and bacteria. We also compare accelerated hinge degradation rates in alkaline solutions of varying pH. These optically transparent containers resemble three-dimensional (3D) micro-Petri dishes and can be utilized to sustain, monitor and deliver living biological components.

In order to fabricate complex origami inspired devices, it is necessary to control folding pathways and enable sequential folding. We demonstrate sequential folding of microstructures from afar by the directed heating of pre-stressed hinges using low power, 40–80 mW handheld, commercial lasers. We observed that the hinge-actuation and consequently folding time varied with laser irradiance, wavelength, and distance. We highlight possible applications by sequential folding of patterned and nested microstructures.

The development of microchemomechanical systems (MCMS) as an analogy to microelectromechanical systems (MEMS) is reviewed, with the distinction that the mechanical actuation of microscale structures is effected by chemical cues as opposed to electricity. The intellectual motivation to pursue MCMS, or the creation of integrated chemical-stimuli-responsive devices, is that such structures are widely observed in nature. From a practical standpoint, since chemicals can readily diffuse and produce changes over large distances, this approach is especially attractive in enabling wireless and autonomous devices at small size scales.

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